Drilling machine



April 11, 1944.

H. E. TAUTZ DRILLING MACHINE Filed June l0, 1941 2 Sheets-Sheet 1 Elm/110M404,

April 11, 1944; H. E. TAUTZ DRILLING MACHINE Filed June 10,- 1941' 2 Patented Apr. 11, 1944 DRILLING MACHINE Herbert E. Tautz, Englewood, 0010., assignor, by mesne assignments, to Delta Manufacturing Comp-any,

Milwaukee, Wis., a partnership consisting of Marshall Field, Charles G. Cushing, and H. Campbell Stuckeman Application June 10, 1941, Serial No. 397,487

' Weight, thereby eliminating all of the above- Claims.

The present invention relates to motor driven tools wherein mechanism for acting on a work piece must be adjusted vertically, for example, a drilling machine or similar device.

In such machines, the mechanism, which may or may not include a source of mechanical power, is often relatively heavy, so that it is very desirable to counterbalance at least a considerable portion of its weight, to enable the operator of the machine to move the said mechanism up and down with less effort, thus making it possible to provide a smoother adjustment and also making it less likely that the mechanism may slip because of too much unbalanced weight.

Heretofore it has been customary to provide counterweights for this purpose. Said counterweights usually are supported from one end of a flexible member, the other end of which is attached to the mechanism, said flexible member passing over a pulley or the like so that the counterweight will support or help to support the weight of the mechanism. Drill presses often make use of hollow columns to support the mechanism, and the interior of this column affords a convenient location for the counterweight, so that consequently drill presses are often made with a counterweight concealed within the supporting column.

However, there are certain disadvantages in this type of counterpoising the unbalanced weight. One disadvantage is that because of the limitations imposed on the dimensions of the counterweight by the bore of the column and the somewhat short unobstructed internal length thereof, it is necessary to make the counterweight of the heaviest material commercially available, that is of lead, since no other material available at any reasonable cost will ordinarily sufiice to afiord sufiicient weight within the dimensions of a counterpoise that will operate within the restricted space available. Another objection is that even with a lead counterweight there is often not suflicient vertical space within the drill column itself, so that it is necessary in uch cases to make the column open at its bottom and to provide a hole in the table or other support upon which such column stands, to provide additional vertical travel for the counterweight. A third objection to the use of lead is the relatively high cost of this metal, and a fourth objection, which applies to any counterweight, is the undesirable increase in weight of the machine as a whole.

The present invention contemplates provid ing a resilient device in place of the counter-,

named objections.

By makin the counterbalancing device as a helical spring, of proper size to be accommodated within the drill column, it is possible to provide a considerably greater range of vertical adjustment than when a counterweight is employed, the weight of the entire machine is considerably decreased, and the expense of providing the lead is eliminated. Thus also it is no longer necessary to provide an open-bottom column for the counterpoise, in alinement with a hole in the table or othersupport.

However, while one feature of the invention thus relates to simplifying the device so as to decrease its weight and its manufacturing cost, it is of course also possible to employ the spring counterbalancing means in the more complicated forms of drill presses and the like, and one particularly advantageous type consists in a mechanism wherein the drill column and. the mechanism carried thereby maybe raised and lowered jointly with respect to the base or table of the drill press, while in addition thereto the mechanism or frame is mounted slidably on such column and counterpoised wholly or partly by means of a spring housed within the column.

This form of machine makes it possible to adjust the height of the frame above the table or base to best suit the work to be done, while providing an additional range of adjustment of the frame by sliding it manually along the column. Preferably a rack is provided to cooperate with the column, and a pinion engaging said rack is mounted in a support carried by the base or table, so that when the pinion is caused to turn about its axis, the rackwill be moved thereby, and will thus correspondingly raise or lower the column and the mechanism mounted thereon. Preferably the pinion is actuated by means of a worm drive, comprising a worm having means for turning it manually, in engagement with a worm wheel mounted on the same shaft with the pinion, thus mutiplying the available lifting force while at the same time constituting a self-locking drive means, because of the worm drive.

The invention also contemplates providing a number of drilling machines mounted on a single table or base, and each embodying any or all of the aboveenumerated features.

It will be understood of course, that while for simplicity, only two drill presses have been illustrated as mounted on a single base or other support, in actual practise there is no limitation imposed on the number of individual machines, which is determined solely by the needs of the shop, and depends upon the number of individual operations which may advantageously be performed upon the work piece in an assembly line, to avoid the loss of time that would otherwise be incurred by resetting or replacing any tool during commercial production.

Other objects and advantages of the invention in part will be pointed out specifically hereinafter, and in part will be self-evident, from the structures disclosed. I p

For the purpose of illustration, preferred embodiments of the invention are described heree in, in connection with the drawings forming a part of such disclosure, and wherein:

Fig. l is a side elevation of a drill press embodying certain features of the invention;

Fig. 2 is a detail view of the top portion of the drill column thereof, partly broken away and partly in central axial section, and on an enlarged scale;

Fig. 3 is a detail view of a fragment of the column near the lower end, this illustration being on the same scale as Fig. 2, and likewise showing the device partly broken away and partly in central axial section;

Fig. 4 is a front elevation showing a fragment of a support, carrying several drilling machines, each otherwise independent of the others, and of the same type as that shown in Fig. l, but with the added feature of a worm-actuated rack and pinion means for raising and lowering the column and its mechanism with respect to the base or table; and

Fig. 5 is a sectional plan view, corresponding to the plane indicated by the line 5-'-5 of Fig. 4.

In all the figures corresponding elements are designated by the same reference characters.

Upon referring to Fig. 1 it will be seen that the machine selected to illustrate the present invention is a bench drill press, of the type wherein the motor for operating the drill spindle is mounted directly on the same support which carries such spindle, so that a simple and efficient connection between motor and drill spindle may be afforded by means of an ordinary belt, thus making it possible to shift the mechanism comprising the spindle of the drill and its source of power jointly up and down the supporting colmm.

This machine consists of a base I, having an upstanding bored lug 2, within which is mounted the cylindrical column 3. Said column may be clamped within the lug in any preferred manner, as by the bolts 4. A frame 5 has a portion 6 which is bored to slide smoothly and freely on the outside surface of the column 3', except when clamped in adjusted position by means of the customary bolt I, having the operating handle 8. A motor mounting plate 9 is carried by the frame 5, for example by means of studs I formed on or secured to the plate 9 and slidably received in the enlarged portions l l which are symmetrically arranged infront of and behind the boredportion 6 of the frame 5. The motor I2 is secured to this plate in any suitable way, as by the cap-screws l3. At the other end of the frame is mounted the drill spindle 14, carried by suitable bearings l5 and having at its lower end a drill holding device such as the chuck 16, while at its upper end it carries preferably a cone pulley IT. The motor carries a corresponding cone pulley l8 so that the belt 19' passing over said pulleys will afford a driving connection between the motor and the drill spindle, said belt surrounding and clearing both sides of the column 3. Suitable retaining means such as the set screws 36 are provided to hold the studs 10 in position, after they have been adjusted to space the motor shaft correctly from the spindle shaft to afford suitable tension of the belt.

An upstanding bearing bracket 20 may be provided at the upper end of the column 3 to support a shaft or pivot 2| carrying a pulley 22. A flexible element 23, here shown as a chain, is at one end connected to the frame at 24 and extends thence over the pulley 22 and into the column 3, where its other end is attached for example, by detachable connecting means 31, to the loop or hook 25 formed at the upper end of the rod 26. The lower end of said rod is threaded as shown at 21, and has a nut 28 mounted thereon.

Attention is now directed to Figs. 2 and 3, wherein the structure within the column 3 is shown on a much larger scale. A retainer member 29 is carried by the rod 26. This retainer has a flange 30 at its bottom, somewhat less in diameter than the bore of the tube 3, said flange serving to retain the lower end of the helical compression spring 3|, as shown clearly in Fig. 3.

The upper end of the spring 3| abuts againstthe bottom of the cylindrical insert 32, which preferably has its central portion of reduced diameter, thus producing narrow flanges 33 at its upper and lower ends. These flanges 33 prefer-- ably fit within the bore of the tube 3 with sufficient clearance to allow the insert 32 to rotate freely about the axis of the column 3 when necessary.

Preferably integral with the insert 32 is the upper flange 34, which extends beyond the outer diameter of the column 3 so as to support the insert 32. This flange 34 carries the bearing bracket 26 already mentioned, which serves as a mounting for the pulley 22. It will be noted that the bearing bracket 28 is bifurcated so as to accommodate the pulley 22 between the bifurcations as shown in Fig. 2. The upper flange 34 may rotate about the axis of the column 3, by rotation of the insert 32 attached to said flange, and thus the pulley 22 may adjust itself, or be manually adjusted, to the proper plane, to cooperate with the position of the frame 5, which may be turned in the usual way about the column 3, in addition to sliding up and down on said column.

The spring 3! is preferably what is known as a low rate spring, that is, its tension increases at a comparatively low rate with respect to its extension or compression. If preferred, the spring may be wound so that its coils must be compressed considerably to fit in place so that a definite predetermined initial push is applied, after which the necessary compression force will increase at such previously mentioned low rate. In this way a more nearly uniform pull will be exerted on the flexible member 23 by the tendency of the said spring to expand, making it possible to approximate the force necessary to counterbalance the weight of the frame 5 and the mechanism carried thereby more closely than with an initially unstressed spring, of necessarily much higher rate.

The retainer 29 may be held on the rod 26 between the nut 28 and a companion nut 35, respectively below and above the retainer.

Referring to Fig. 2, it will be noted that a screw 38 may be threaded through the upper end of th column 3, so that the inner end of the screw will project into the groove at the center of the Cylindrical insert 32. The purpose of this screw is to prevent accidental removal of the insert from the column during shipment of the machine and also to prevent such insert from being pushed out of the-column 3 by .the compression spring 3| in casethe flexible element 33 should break or become disengaged at either end. Normally there is no tendency of the insert 32 to leave the column 3, as it is held down by the weight of the frame 5. This screw 38 may have its threaded portion long enough to engage the insert 32 if desired, in which case it should be loosened before operating-the machine, or may extend only far enough through the column 3 to prevent removal of the insert. The screw is not in any way essential to the operation of the drilling machine, but as stated is merely a precautionary device which may be desirable during assembly, shipment, dismantling, etc;, of the machine. 1

Attention is called also to the fact that the entire mechanism, including the frame and the parts carried thereby as well as the spring, pulley, and flexible member associated with the insert 32 may be removed from: the column 3 as a unit by merely lifting the frame 5 upwardly, whereupon the flange 34 will catch on top of the frame 5, carrying with it the flexible member 23, the spring 3| and said associated parts. This feature may be found very convenient duringassembly and repairing the device, for example.

Various types of operation are possible, that is the spring and its adjustments may be such that the weights of the frame 5 and the parts carried thereby are fully counterpoised when the said frame is at some given position along the column 3, for example at the top, middle or bottom of its range of adjustment. In general it will probably be preferable to have it exactly counterbalanced at its mid position or at the top of its range, thus in the last named case :avoiding any need of lifting the weight of the frame when it is desired to raise it, and also :avoiding any accidental dropping of the frame iii" the clamping lever 8 is released inadvertenly. While the flexible member 23 is disclosed as a chain, obviously any other flexible connection I 'could be substituted if necessary for reasons of economy, 'such as a flexible cable, a metal tape, or even a rope or cord.

Referring now to Figs. 4 and 5, two drilling machines mounted upon a single base or table 40 are there shown. Each of these drill presses has a hollow column 4| corresponding to the column 3 of Fig. 1 and housing a spring 3| identical with that of Fig. 1. Instead of the simple tubular lug 2 of Fig. 1 however, in Fig. 4 a wormdrive support 42 is provided for each column 4|.

Each column 41 preferably has a rack bar 43 attached thereto, as best shown in Fig. 5 and a pinion or gear 44 is in mesh with the teeth of such rack. The pinion 44 is mounted on a shaft 45, which also carries a worm Wheel 46, said elements 44, 45 and 46 being rigidly connected with one another, preferably by making the whole of a single piece of metal.

At the ends of the shaft 45 there are reduced journal portions 41 and 48, which are mounted to turn in suitable bearings formed in or carried by the support or casing 42. A second shaft 49, extending at right angles to the shaft 45 and likewise mounted in bearings of the support 42, carries a worm 50 in engagement with the teeth of the worm wheel 46, so that rotation of the shaft 49 will cause said worm wheel to turn.

The shaft 49 preferably extends out of the casing 42 at one end and terminates in a squared portion 5!, which may be engaged by any suitable key or crank handle having a correspondingly shaped socket therein. Thus rotation of the shaft 49 will cause the shaft 45 to turn slowly but with relatively great power, and will thereby raise or lower the corresponding column 4| by means of its rack bar 43. It will be seen from Fig. 4 that in this form of machine the columns 4! extend through the table top 40, and continue beneath the same.

In this way the column of each drill press may be preliminarily adjusted up or down to the proper height to best accommodate the work pieces to be drilled, whereupon any further adjustments of the height of each frame 5 may be made as in the Fig. 1 form, by merely releasing the corresponding clamping lever 8 and sliding the entire mechanism up or down manually to suit the work being done.

It will be understood that this multiple arrangement of drill presses is not necessarily confined to two machines but that any desired number may be assembled to suit the requirements of the shop. The worm mechanism is of course self-locking and therefore the column 4| of each drill press will remain automatically in its adjusted position.

Each type of adjustment has its own characteristic advantages, that is, the worm mechanism will provide great lifting power with relatively small efiiort applied to the operating handle, 'in addition to the self-locking feature, while on the other hand the manual shifting of the frame 5 and the mechanism carried thereby requires somewhat more effort, but is relatively quick; The combination of both forms of adjustment is therefore extremely advantageous, and fits the assemblage for a greater variety of Work than could be accomplished most efficiently by each separately.

The operation of the drilling machine in its various forms will presumably be understood from the disclosure of its structural features, but for completeness may be summarized as follows:

Referring first to the simpler type disclosed in Figs. 1, 2, and 3, the belt I9 will be placed in the proper steps of the cone pulleys I1 and I8 to give the desired speed of rotation to the spindle I4 and the chuck I6 carried thereby. The motor 12 is controlled by the switch 52, which in turn is operated by the extension rod 53, the forward end 54 of which extends within convenient reach of the operator.

After placing the proper drill bit or other tool in the chuck IS, the entire frame 5 will be raised or lowered manually to the proper height to cause such tool to cooperate with the work piece supported on the table I. In order to make it possible to raise or lower the frame 5, the handle 8 will be actuated to loosen the frame on the column 3, to permit it to slide up or down as necessary, whereupon the screw 1 is again tightened by means of its handle 8. The quill 55 which carries the drill spindle may be raised or lowered in the usual way by turning the shaft 55 by means of the customary handle 51, and the extent of vertical motion of the quill will be indicated by the adjustable pointer 58, clamped under the screw 59.

The belt may be tightened or loosened when necessary by loosening the screws 36 and sliding the short stud shafts l out or in, whereupon the screws 36 may be tightened again.

Usually the column 3 will be maintained in clamped condition within the tubular support 2 by means of the screws 4, which may however be released when necessary to provide for any readjustment of such column,

, When moving the frame up or down manually some or all of the load will be supported by the spring 3!, acting through the flexible element 23, as already explained.

When the frame 5 is to be rotated about the axis of the column 3, in order to shift the drill spindle M from What may be called its normal position, this is readily possible upon loosening the screw '1, and in the course of such rotation the head 32 will turn within the column 3, to permit the pulley 22 to adjust itself into the new central plane of the frame 5, assuming that the set screw 38 has been removed, or loosened.

Referring now to the multiple drill press illustrated in Figs. 4 and 5, it is obvious that each of the individual machines may be operated in the same way as the single drill press of Figs. 1, 2, and 3, to the extent that these structures are substantial duplicates of one another.

The operation of the multiple drill presses illustrated diilers however from that of the simpler type of Fig. l in that the additional feature of rack and pinion adjustment and worm gear drive is here provided, as well as the feature of having the drill columns extend completely through the base or support 50. By placing a proper handcrank, key, socket-wrench, etc. on the squared head 5!, the worm 5E3 may be actuated to raise or lower the column 4! smoothly and easily, said column remaining automatically in any position of adjustment because of the self-locking action of the Worm drive,

The individual drill presses constituting the multiple drilling machine may thus be adjusted to the proper positions for the operation each is intended to perform on the work piece, whereupon any further adjustments may be made by moving the frame 5 directly by hand, as in the Fig. 1 form.

In order to prevent inadvertently raising the column 4| too high by the worm mechanism, a safety collar 5% may be secured to the column 4! below the table 45, by means of a set screw 60 or equivalent device. The columns It! may also be clamped at any desired height by the screws 4, just as in the Fig. 1 form.

Having disclosed the invention and. illustrated several specific embodiments thereof, it should be clearly understood that such illustrations are given only by way of example, and are not to be considered as in any way limiting the scope of the invention, which is defined solely in the following claims.

I claim:

1. In a machine tool, a support comprising a base and a substantially vertical portion carried by said base, mechanism carried by and adjustable along said portion, means for carrying at least a part of the weight of said mechanism, comprising a resilient extensible element connected to said mechanism, said means being housed at least in part in said substantially verticalportion of the support, said vertical portion of the support being movable longitudinally with respect to the said base, and gearing interposed between said vertical portion and said base, for raising or lowering said vertical portion with respect to the base.

2. A drilling machine, comprising a base, a vertical hollow column carried by. said base, drill operating mechanism carried slidably on the column, means housed in part within the column for counterbalancing at least a part of the weight of the mechanism, the column being axially movable with respect to the base, and gear mechanism interposed between the base and the column for adjusting it vertically,

3. A drilling machine, as defined in .claim 2, wherein the drill column extends entirely through the base, thereby increasing the available range of vertical adjustment.

4. A drilling machine, comprising a base, a substantially vertical hollow column mounted for axial movement in said base, drill operating mechanism carried by and movable along said column, resilient means housed within the column, and means whereby such resilient means cooperate with said mechanism to counterpoise at least a portion of the weight thereof to facilitate manually moving the mechanism along the column, a rack extending along andconnected to the column, a pinion in mesh with the rack, means comprising a worm drive for turning said pinion, and a casing carrying said pinion and worm drive and mounted on said base, whereby the mechanism may be adjusted directly manually, and also indirectly through the worm drive.

5. A drilling machine comprising a base and a substantially vertical hollow column, drill operating mechanism carried by said column, and movable therealong and also rotatable around said column, a helical spring housed within the column, a flexible member heaving one end secured to the said drill operating mechanism and its other end secured to the lower end of the spring, a support bearing against the upper end of the spring to maintain it at a fixed elevation, said support being mounted on the column to turn about the axis of the column, a pulley journaled in said support, said flexible member passing over the pulley, whereby the end secured to the mechanism moves in the opposite sense to the other end, and whereby the pulley may follow the rotation of the said mechanism about the column, said spring operating wholly in compression, and even in its most relaxed condition supporting substantially the entire weight of the said mechanism.

6. A drilling machine as defined in claim 5, wherein the support has a projecting portion extending radially beyond the column, whereby the dril1 operating mechanism will strike the said portion when at the top of the column, thereby eliminating the lifting action of the spring and thus preventing inadvertent excessive upward adjustment of the mechanism.

'7. A vertically adjustable drill operating mechanism for a drillin machine having a hollow vertical column, and a counterbalancing device for said mechanism, said device comprising a helical compression spring adapted to be housed in a part of the said machine, a support resting by gravity on the upper end of said column, a pulley carried by said support, a flexible element extending over said pulley and having one end connected to the mechanism and its other end to the lower end of the spring, the upper end of the spring bearing against said support, and means projecting from said support to engage said mechanism at the upper limit of its permissible vertical adjustment, whereby further lifting of said mechanism beyond said upper limit will remove the entire counterbalancing device from the machine therewith.

8. In a drilling machine, a base, a colunm, and drill operating mechanism carried by said column, said base having a hole extending entirely therethrough in a substantially vertical direction, said column being slidably received in said hole and projecting axially beyond both ends of the hole, gearing for adjusting said column axially to vary the amount it thus projects, a safety stop, and means to secure said stop to the column below the base, to prevent excessive raising of said column.

9. In a drilling machine having a hollow vertical column carrying a drill head guided for movement from a raised position adjacent the top of said column to a lowered position spaced materially therefrom, a, helical compression spring of materially greater length than said column disposed within said column; means for maintaining said spring compressed to a length shorter than said column and applying the forces, set up by the tendency of said sprin to expand, to said head, so as to exert substantial counterbalancing forces upon said head in all adjusted positions thereof; comprising an assembly at the upper end of said column against which the upper end of the spring bears, said assembly also having pulley means thereon, a flexible force transmitting member anchored to the lower end of said spring and passing upwardly in said column through said spring and passing over said pulley means and downwardly outside of said column; and means connecting said flexible member to said head, whereby as the latter is moved downwardly on the column the lower end of said spring will be dis placed upwardly in the column and greater compressive forces set up in the spring.

10. In a drilling machine having a hollow vertical column carrying a drill head guided for movement from a raised position adjacent the top of said column to a lowered position spaced materially therefrom, a helical compression spring of materially greater length than said column discomprising an assembly at the upper end of said column against which the upper end of the spring bears, said assembly also having pulley means thereon, a flexible force transmitting member anchored to the lower end of said spring and passing upwardly in said column through said spring and passing over said pulley means and downwardly outside of said column; and means connecting said flexible member to said head, whereby as the latter is moved downwardly on the column the lower end of said spring will be displaced upwardly in the column and greater compressive forces set up in the spring and means, operably associated with said assembly, for preventing said spring from pushing said assembly oil, of the top of said column in the event that said flexible member should break or become disengaged from either said spring or said head.

HERBERT E. TAUTZ. 

